To check, you can head over to Samsung’s Note 7 IMEI checker where you can insert your IMEI or serial number to verify whether or not your device is affected by the recall. The same page also hosts carrier-specific contact information for the exchange program.

You can find your IMEI or Serial number by going to the Settings app, then tapping About Phone. Or you can go to General Management > Status > IMEI information or Serial number.

The basic rule of thumb with this recall if that if you purchased your device before September 15th, 2016 (aka today), you’re going to need to switch out the phone.

That said, this tool will come in handy when the device goes back on sale later this month and even more so if you’re purchasing the phone second-hand at any point at all. Samsung says it plans to have new phones (that don’t explode, hopefully) in stores sometime in the next week.